The Swann v. Adams case of 1965 was a significant U.S Supreme Court decision that dealt with the issue of legislative redistricting in Florida. The plaintiffs, led by Swann, argued that the state's apportionment plan violated their Fourteenth Amendment rights to equal protection under law because it resulted in unequal representation due to population disparities among districts. The defendants were representatives from the State of Florida who defended the existing districting scheme. Initially, lower courts upheld Florida’s reapportionment plan but on appeal, the Supreme Court reversed this decision and ruled in favor of Swann and his co-plaintiffs. In its ruling, the court held that any state legislation which diluted an individual's right to vote or diminished their political efficacy contravened constitutional principles relating to equality before law and democratic governance.

In the dissenting opinion for Swann et al. v. Adams, Justice Harlan argued that the Supreme Court overstepped its boundaries by involving itself in state legislative apportionment issues, which he believed should be left to individual states and their legislatures. He expressed concern about the potential consequences of such involvement on federalism principles and warned against judicial intrusion into political matters best handled by elected officials who are accountable to voters. Furthermore, he criticized the majority's decision as lacking clear standards or guidelines for lower courts to follow when evaluating whether a state's redistricting plan violates equal protection rights under Fourteenth Amendment. In his view, this lack of clarity could lead to arbitrary decisions based on personal preferences rather than constitutional law.